Cole Hamels Staying Grounded

Cole Hamels carved up the Los Angeles Dodgers on Wednesday night. The lefty punched out nine batters and walked none in eight shutout innings, lowering his Fielding Independent Pitching (FIP) to 2.31 in the process. Even considering the lower run-scoring environment in baseball right now, Hamels is in the midst of his best season in the majors. His FIP is 38 percent better than the league average in 2011 (68 FIP-), which ranks second only to teammate Roy Halladay among qualified starting pitchers.

The already-elite Hamels has raised his game to a new level this year by keeping the ball on the ground more often. That, in turn, has significantly cut his home run rate and limited other types of extra base-hits for the opposition.

Entering the year, Hamels had induced ground balls 41.3% of the time during his career. In 2011, Hamels has scorched the earth 52%. That’s well above the 45% major league average and ranks in the top 20 among qualified starters. Changes in ground ball rate become significant after about 150 batters faced. Hamels has squared off against 351 hitters this year, so his uptick in grounders looks legit.

How is Hamels keeping the ball down? Check out his ground ball rate by pitch type over the 2010 and 2011 seasons:

Hamels is getting many more grounders with his fastball this year, while also boosting his ground ball rate on cutters and curveballs thrown. His changeup already got a lot of grounders and has continued to do so in 2011. Hitters are putting the ball in the air less often against Hamels, which has helped the 27-year-old decrease his slugging percentage on contact nearly across the board. In particular, look at the fastball and cutter:

(The high slugging percentage on contact for Hamels’ changeup will likely surprise you, but keep in mind that the sample size isn’t huge with the pitch because batters whiff at the pitch so frequently — about 28% of the time that he threw it in 2010, and 30% this season).

With the extra grounders, Hamels has surrendered extra-base hits to a career-low 5.7% of batters faced (7.9% MLB average) and has given up 0.5 homers per nine innings pitched (he had served up 1.16 HR/9 entering the 2011 season).

Hamels probably won’t be quite this dominant in the months to come — his .268 batting average on balls in play is 18 points below the big league average, and his 6.9% home run per fly ball rate is a bit below the eight percent MLB average — but his increased ground ball rate makes him a better pitcher overall. When a guy makes his home starts in Citizens Bank Park, a venue that boosts home run production by 16% for lefties and 20% for righties, staying grounded is a winning strategy.